Scanlab RTC6 PCIe Board - Laser Control

RTC6 boards
Doc. Rev. 1.0.21 en-US
8 Advanced Functions for Scan Head Control and Laser Control
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8.7.3 Laser Control
Depending on the type of laser employed, the laser
energy outputted at each pixel position can be varied
by:
• laser pulse length
• laser power per pixel
“Classic Mode”
The “Classic Mode” (Mode = 0, see Channel )
corresponds to the Pixel Output Mode of the RTC4
and RTC5. Maximum pixel output frequency:
400 kHz.
• Variation Of Laser Pulse Length: set_pixel defines
– for each pixel – the length of the pixel pulse (in
units of 1/64 µs), which is outputted at the
LASER1 port. For synchronization, see
Chapter 8.7.4 ”Synchronization”, page 268.
• Variation Of Laser Power: set_pixel allows
specification of a 12-bit analog voltage level for
each pixel. The value is transferred either to the
ANALOG OUT1 or ANALOG OUT2 output port
(see above). For synchronization, see
Chapter 8.7.4 ”Synchronization”, page 268.
set_n_pixel defines the analog voltage level for n
directly successive pixels of an image line.
“Extended Mode”
In “Extended Mode” (Mode = 16, see page 712),
two pixels (32-bit values) are outputted at the
specified port with each set_pixel. Maximum pixel
output frequency: 800 kHz.
“Fast Mode”
In “Fast Mode” (Mode = 32, see page 712),
4 pixels of 16 bits each are outputted at the specified
port with each set_pixel. Maximum pixel output
frequency: 1.6 MHz.
“Ultra Fast Mode”
In “Ultra Fast Mode” (Mode = 64, see page 712)
8 pixels of 8 bits each are outputted at the specified
port with each set_pixel. Maximum pixel output
frequency: 3.2 MHz.
Notes
• Pixel output frequencies > 800 kHz (“Fast Mode”
and “Ultra Fast Mode”) require the Option
“UFPM“. Otherwise, the pixel output frequency is
clipped to 800 kHz.
• It is recommended that some experiments be
performed to determine an appropriate
gradation curve for producing smooth greyscales.
The resulting pixel greyscale values (“colors“)
strongly depend on the employed material and
the laser.
• The LASERON signal – as with a normal
[*]mark[*] Command – switches to “On” after the
LaserOn Delay has expired and remains ”On” for
the entire pixel line. After the last pixel has been
outputted, it automatically goes to “Off”. See
Chapter 7.4 ”Laser Control”, page 184.
• The LASER1 signal depends on the respective
laser mode and the associated settings, as well as
on the Mode (see page 712) set by
set_pixel_line/ set_pixel_line_3d: A periodic
signal with HalfPeriod from set_pixel_line and a
PulseLength from set_laser_pulses (however, at
least 1/64 µs long) is outputted. The following
exceptions apply:
– In Laser Mode 4 and Laser Mode 6, only a
standby signal is outputted that cannot be
varied. Power changes are only possible via the
output ports ANALOG OUT1, ANALOG OUT2,
8-bit digital output port (EXTENSION 2) or
16-bit digital output port (EXTENSION 1).
– If an output to PulseLength is specified as the
Mode, PulseLength is varied per pixel.
– No Softstart is performed, see Chapter 7.4.7
”Softstart Mode (not yet implemented)”,
page 195.
• The LASER2 signal follows the specifications of
the respective laser mode.
• Pixel Output Mode and Sky Writing cannot be
combined. However, a separate
Sky Writing Mode 1-like galvanometer scanner
movement can be inserted, see Figure 65.
• The values for HalfPeriod and PulseLength set
prior to set_pi
xel_line are not restored again.
se
t_laser_pulses must be explicitly called again.